I bought recently Construct 2 to develop games, but I have a major problem to solve it...

As you know, we have many types and sizes of our screen displays, CRT, LCD, cubic sized (4:3), panoramic sizes (16:9) etc. Also we have different preferences of display, some of us prefer high resolutions (+ 1920x1080), low res (1366x768) and perhaps much lower (Yes, I know someone who is working on 800x600 res).

My question is. What most flexible layout size wil be on our screens without much loosing quality on images used in game?

Don't know if this is a best approach but i always set window size to 1280x720, layout "Unbounded scrolling" to Yes and "Fullscreen" to scale outer. Then I manipulate my images to fit current device resolution. It's been working great for me on desktops and mobiles with same/lower/higher resolutions.